This is not something I have ever done to any car. I am the most car-sympathetic driver in the world -- but I do a very small mileage slowly generally because of where I live.
So in the interests of giving my engine a chance to avoid more expensive trouble later I thought I might do a carefull well considered medicinal thrash.
So what do I do please?
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Just rev it a bit more. Hold the gears to 4000 rpm instead of 3000, sit at 70 in 4th rather than 5th for a few miles. Main benefit in my Xantia is to blow the dust out of the exhaust.
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You toodle around for half an hour, getting it all nicely warmed up and loose. Make sure you are topped to the mark with oil.
then you either:
a: find somwhere you can pretend you are starting a gran prix away from the lights, and take it up to 60 or 70 mph through the gears, reving it to about 500 revs below the red line each time.
or
B: toddle on to the motorway, and run it along at 70mph in whatever gear is about 500 revs under the red line, say 3rd. For about a mile or so.
Do this twice a month to clear its lungs
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And like AE says - make sure it warm before you rev the nuts off.
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Several years ago I rented a non-turbo-diesel Fiat Doblo whilst on holiday. I knew it would be slow, but it was incredibly slow, ridiculously slow, dangerously slow in fact. I took it by the scruff of its neck and drove it like a maniac the whole time I had it (I still didn't get much over the posted speed limits!). By the end of the holiday it was performing far better, making lots less smoke and was far more capable of keeping up with traffic.
So yes, get the engine nice and warm and thrash it big time, making certain you are doing so safely and without going too fast.
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"So yes, get the engine nice and warm and thrash it big time, making certain you are doing so safely and without going too fast."
I think the technical term for this is an "Italian Tune up"
I use it on my French diesels!
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making certain you are doing so safely and without going too fast.
What exactly is 'too fast'?
There's no such thing.
Do by all means go 'too fast' - LOL - but don't get noticed by the authorities or one of the increasing band of voluntary sneaks who are sneaking around in ever-increasing numbers (may they meet dangerous and competent psychopaths sooner rather than later).
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One other tip to enhance the life expectancy of a turbo-diesel; once you've fired it up, let it run on tickover for at least half a minute, ideally longer. Most people are aware of that one.
What they DO tend to forget is to do the same thing at the end of your journey. It's considered best practice on truck engines, so it certainly won't do a car engine any harm. Prevents the turbo from going bang.
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Some info mentioned in HJ's FAQ's; the latter half of 'running in a diesel'
www.honestjohn.co.uk/faq/faq.htm?id=32
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SFAIK this turbo cooling period only really applies if you have been sailing down a motorway and turn into a service area? My runs home involve minimum 5 minutes @ 30 mph so I guess the turbo is already 'cooled' by the time I park up. Standing by for correction!
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Correction not required ;)
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It is actually the engine speed and not the road speed that is critical.
Mine is doing around 2000 revs at 70 on the motorway, nearly as many in third at 30 - Turbo would be at similar temperature.
Probably not necessary to give it the time unless it has been running at 3000-4000 revs for a period but that is illegal over here in fourth or fifth!
It has done 117k.
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I always let both the Scenic and Mondeo idle for 20-30 seconds before switching off, and that's after a mile or so of 20-30 mph residential area motoring. It's just habit - whether it does any good or not I don't know. I must admit though, I drive off within 10 seconds of the engine firing up.
The Scenic's engine in particular seems to relish being thrashed. It's not a smoky engine any time, but after a good caning it sharpens up part throttle response considerably and idles smoother. Neither SWMBO or I drive gently anyway, and both cars spend far more time on motorways and A-roads than in town, but we make a point of exploring the upper end of the rev range quite frequently in both cars. The difference it makes to the Mondeo is much smaller, and is mostly in the way of reduced smoke under hard acceleration, and in terms of slightly keener response at the bottom end of the rev range.
The most dramatic improvement to the Mondeo is the first 1,000 miles after an oil change where it feels literally like a new engine.
Cheers
DP
Edited by DP on 09/01/2008 at 08:55
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Driving hard is not thrashing;I regularly drive my TD the length of France at 80-90 mph.It thrives on it.There is a lot of correspondence on HJ about clogged up turbos-what they need is to be driven.When you first start,let the engine idle but 30 secs. is plenty-modern oils will have reached all parts by then(normally within the first ten)-similarly,unless your house is on a motorway,the drive around local roads at 25-30 mph.will cool the turbo down sufficiently for immediate switch-off.It is uually only the fuel stations on German autobahns that require a cooling period-on most of them the pumps come first-most French autoroute service stations have a sufficiently tortuous access to the pumps that the turbo has cooled.
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I covered 200 miles in my 306TD today, with around 150 of those being driven at around 80-85mph which is some 10mph faster than I usually drive and really giving it some stick when overtaking i.e. 60 in 3rd on numerous occasions. This seems to have made a difference already in terms of less smoke and a slightly increased throttle response at lower revs. However, the fuel economy certainly suffered and I used around 26 litres for the 200 mile run!
Martin
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The fuel economy on the 306 td really takes a nose dive after 70mph, when cruising higher...nevermind the racket that engine produces at above 70 speeds!
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Try to take it up to max power at least twice a week in your circumstances. You dont have to redline as theres no point, engine runs out of air/fuel mix so max power is adequate. If you dont know where max power is, you can feel when the engine starts to drop off with power.
Because i do decent millage each day i get up to max power in any gear at least once on the trip and from work.
I also vary the revs a lot. Mainly changing around 2.2krpm, then sometimes at 3k then once or twice up to max power, 4.2k and then back down again.
Most important things for me with a diesel is, 10/15secs start up idle, eco driving, no hard revving until engine is fully warm and at least a 15sec cool down time after each journey. 1min cool down after harder driving and if i go over to wales on the backroads, 2 mins cool down :) ... all that hill driving. Max power on each journey but limited to 2nd gear. 3rd gear at max power would be way over the NSL for roads.
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